Apple Files Lawsuit Against Oppo Over Alleged Trade Secret Theft Involving Former Apple Watch Engineer
Apple has launched a lawsuit against Chinese consumer electronics giant Oppo, accusing the company of orchestrating a scheme to steal its trade secrets by poaching a key member of the Apple Watch engineering team.
According to court filings, Apple — represented by powerhouse law firm Kirkland & Ellis — claims that its former sensor system architect, Dr. Cheng Shi, improperly took sensitive knowledge with him when he left the company. Dr. Shi, who played a significant role in the development of sensor technologies for Apple Watch, is now employed by both Oppo in China and its U.S.-based affiliate Innopeak.
Apple alleges that Shi’s move was not a routine career switch but part of a deliberate attempt to gain access to Apple’s proprietary sensor systems, which are crucial to the health and fitness features that have helped differentiate the Apple Watch from rival smartwatches. The lawsuit suggests that by hiring Shi, Oppo and Innopeak may have benefited from privileged insights into Apple’s internal designs and innovations.
The case underscores the growing tension between U.S. and Chinese tech firms, where intellectual property and trade secrets have become central to competition in areas like wearables, AI, and smartphones. Apple has historically taken a hard stance in defending its patents and technology, with high-profile battles against companies such as Samsung. The move against Oppo highlights Cupertino’s continued resolve to safeguard its ecosystem against what it views as unfair competitive practices.
If successful, Apple’s lawsuit could have significant implications for Oppo’s smartwatch ambitions, potentially limiting its ability to compete in markets outside of China. It also reinforces a broader industry trend: as the smartwatch sector matures, the fight for ownership of health and biometric innovations is becoming more aggressive — and more litigious.
Apple Alleges Former Watch Engineer Shared Sensitive Health Tech With Oppo
According to a complaint filed Thursday in the U.S. District Court for the Northern District of California, Apple claims that Dr. Cheng Shi — a former senior engineer — is now leading a team at Oppo’s U.S. office focused on developing advanced sensing technologies.
What exactly is Shi accused of doing?
Apple alleges that during his tenure at the company, from January 2020 to June 2025, Dr. Shi was more than just an employee — he was given what Apple describes as “a front-row seat” to its most confidential projects. This included access to sensitive roadmaps, internal design documents, development specifications, and prototype data related to the Apple Watch’s health and fitness features.
Central to Apple’s concern is its ECG (electrocardiogram) sensor technology, a flagship feature that allows Apple Watches to monitor heart activity and detect irregular rhythms. Apple contends that Shi’s deep knowledge of this system — along with upcoming health-focused innovations that had not yet been released publicly — could give Oppo an unfair competitive advantage as it ramps up efforts to expand its own wearable device ecosystem.
In its filing, Apple emphasizes that the information Dr. Shi had access to was highly confidential and protected by strict nondisclosure agreements. By allegedly taking this expertise to Oppo, Apple claims Shi may have compromised years of research and billions in R&D investments.
The case isn’t just about one engineer; it highlights the growing battleground over health tech in wearables. Apple has long positioned the Watch as a medical-grade device in the making, pushing into areas like heart monitoring, blood oxygen tracking, and even glucose measurement. Oppo, meanwhile, has been aggressively investing in similar technology, seeking to challenge Apple and other smartwatch leaders like Samsung.
If Apple’s allegations prove true, the outcome could impact how Big Tech companies police employee transitions, especially in areas where intellectual property and health-related technologies intersect.
In its complaint, Apple alleges that Dr. Cheng Shi secretly copied 63 confidential files from the company’s internal shared drive onto a personal USB drive — just three days before resigning. The documents, Apple says, contained not only information about the technological capabilities of unreleased products, but also detailed hardware and software specifications for the Apple Watch’s health sensors, including its temperature-sensing features.
The filing also points to Shi’s alleged internet search history, which reportedly showed queries such as “how to wipe out MacBook” and “Can somebody see if I’ve opened a file on a shared drive?” — searches Apple claims are clear evidence of intent to cover his tracks.
But Apple’s accusations don’t stop with the Watch. The company also asserts that Shi misappropriated highly confidential data from its custom silicon team. Apple has invested heavily in developing its own in-house processors for Macs, iPhones, and iPads, and has more recently been channeling resources into building specialized AI chips. This project, described internally as critical to CEO Tim Cook’s broader AI strategy, represents one of Apple’s most important long-term bets.
By allegedly taking this knowledge to Oppo, Apple contends, Shi could jeopardize years of proprietary research and potentially accelerate a competitor’s push into both wearable health tech and AI-driven chip design.
Oppo’s History with Apple — and Why This Case Matters
Oppo, best known for its sleek smartphones and aggressive push into wearables, has long drawn comparisons to Apple. In 2020, the China-based company faced criticism after unveiling a smartwatch that many online derided as an Apple Watch clone.
While Oppo’s smartphones don’t yet rival iPhones in brand prestige or global sales, they perform exceptionally well in Asia, especially in China — one of Apple’s most critical markets. Together with Huawei and Xiaomi, Oppo has steadily eroded Apple’s market share in China, contributing to Apple’s slip out of the country’s top five smartphone vendors in 2024.
But Apple has recently regained ground. According to Reuters, citing preliminary third-party data, iPhone sales climbed back to the No. 1 spot in China in May 2025, fueling a rebound in Apple’s global sales. That turnaround underscores just how high the stakes are in Apple’s fight to protect its intellectual property from competitors like Oppo.
Although Oppo doesn’t sell its smartphones in the U.S., Apple notes in its complaint that the company maintains a Silicon Valley “research center” under both Oppo and its California-based subsidiary Innopeak — the very entities now named in Apple’s lawsuit.
What Does Apple Claim?
According to the filing, evidence from Dr. Shi’s work-issued iPhone revealed communications with senior Oppo executives between April 2025 and his resignation in June. In one alleged message, Shi told leadership:
“This week I’ll inform my team about my resignation. Lately, I’ve also been reviewing various internal materials and doing a lot of 1:1 meetings in an effort to collect as much information as possible – will share with you all later.”
Apple further alleges that in the month before leaving, Shi scheduled 33 one-on-one meetings across projects outside his scope of work — a sharp spike compared to his usual seven per month just a year prior.
When he finally resigned, Apple says, Shi misled colleagues by claiming he was returning to China to care for his elderly parents and had “no plans to seek new employment.” In reality, Apple alleges, he was preparing to lead a new Oppo team working on sensor and health-monitoring technologies — the same space he had worked on at Apple.
What Apple Wants
Apple is asking the Northern District of California to issue an injunction blocking Oppo and Innopeak from using any stolen trade secrets, while also seeking restitution and damages to be determined at trial.
If successful, the lawsuit could not only shield Apple’s crown jewels — its health tech and custom chip designs — but also send a broader message across Silicon Valley and China’s fast-moving consumer electronics sector: Apple is ready to aggressively defend its IP at all costs.